WO2007130421A2 - A braking or clutching device - Google Patents
A braking or clutching device Download PDFInfo
- Publication number
- WO2007130421A2 WO2007130421A2 PCT/US2007/010565 US2007010565W WO2007130421A2 WO 2007130421 A2 WO2007130421 A2 WO 2007130421A2 US 2007010565 W US2007010565 W US 2007010565W WO 2007130421 A2 WO2007130421 A2 WO 2007130421A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- housing
- armature
- electric braking
- air gap
- clutching device
- Prior art date
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16D27/00—Magnetically- or electrically- actuated clutches; Control or electric circuits therefor
- F16D27/10—Magnetically- or electrically- actuated clutches; Control or electric circuits therefor with an electromagnet not rotating with a clutching member, i.e. without collecting rings
- F16D27/108—Magnetically- or electrically- actuated clutches; Control or electric circuits therefor with an electromagnet not rotating with a clutching member, i.e. without collecting rings with axially movable clutching members
- F16D27/112—Magnetically- or electrically- actuated clutches; Control or electric circuits therefor with an electromagnet not rotating with a clutching member, i.e. without collecting rings with axially movable clutching members with flat friction surfaces, e.g. discs
- F16D27/115—Magnetically- or electrically- actuated clutches; Control or electric circuits therefor with an electromagnet not rotating with a clutching member, i.e. without collecting rings with axially movable clutching members with flat friction surfaces, e.g. discs with more than two discs, e.g. multiple lamellae
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16D65/00—Parts or details
- F16D65/14—Actuating mechanisms for brakes; Means for initiating operation at a predetermined position
- F16D65/16—Actuating mechanisms for brakes; Means for initiating operation at a predetermined position arranged in or on the brake
- F16D65/18—Actuating mechanisms for brakes; Means for initiating operation at a predetermined position arranged in or on the brake adapted for drawing members together, e.g. for disc brakes
- F16D65/186—Actuating mechanisms for brakes; Means for initiating operation at a predetermined position arranged in or on the brake adapted for drawing members together, e.g. for disc brakes with full-face force-applying member, e.g. annular
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16D2121/00—Type of actuator operation force
- F16D2121/02—Fluid pressure
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16D2121/00—Type of actuator operation force
- F16D2121/14—Mechanical
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16D2121/00—Type of actuator operation force
- F16D2121/18—Electric or magnetic
- F16D2121/20—Electric or magnetic using electromagnets
Definitions
- Devices used for braking or clutching are common in industry. It is often desirable to selectively control speed or torque of a rotatable component of a device or to selectively engage a rotatable component. Such devices are utilized in industry for many and varied applications including actuators in assembly lines, automated systems, etc.
- An electric braking or clutching device includes a housing; an armature having an axis and disposed at the housing, the armature and the housing defining a radial air gap therebetween; and a coil configured to generate, when energized, a magnetic field at the housing and armature, a flux path of the field extending from the coil into the armature, from the armature into the housing, and from the housing back to the coil, with the direction of the flux path from the armature into the housing being substantially radial in orientation.
- a braking or clutching device includes a first plurality of discs rotationally fixed to one of a housing or a shaft; and at least one second disc interengaged with the first plurality of discs and rotationally fixed to the other of the housing or the shaft, at least one of the first plurality of discs and the at least one second disc presenting a contact surface, for contact with another of the first plurality of discs and at least one second disc, the surface comprising a low friction bearing material having a kinetic coefficient of friction substantially the same as its static coefficient of friction.
- a magnetically actuable device includes a housing; and an armature disposed at the housing and axially movable relative to the housing, the device having a substantially uniform magnetic actuation force sustainable through a majority of an axial movement of the device irrespective of wear of the device.
- Figure 1 is a cross section view of a selective engagement device
- Figure Ia is a plan view of the device illustrating the section line for figure 1;
- Figure 2 is a perspective view of a shaft of the device
- Figure 3 is a perspective view of an armature of the device
- Figure 4 is a perspective view of a housing of the device
- Figure 5 is a plan view of a thrust washer of the device
- Figure 6 is a plan view of a friction disk of the device.
- Figure 7 is an enlarged view of circumscribed area 7-7 in figure 1.
- Figure 8 is the view of Figure 7 with the flux path illustrated by a heavy black line.
- a selective engagement device 10 is generally depicted in cross section. It is important to note that the section line as depicted is not a diametral line but rather is that illustrated in figure Ia.
- the device includes a coil housing 12 and cover 14. Supported within the coil housing 12 and cover 14 are a rotary shaft 16 supported by bearings 18, 20 and 22.
- a retention ring 24 is positionable in a groove 26 adjacent to bearing 22 while retention ring 28 is positioned in groove 30 adjacent bearing 18 to retain the shaft 16 in its desired position relative to the housing 12 and cover 14. Further provided is a seal 32 to maintain the environment internal to housing 12 and cover 14.
- a plurality of friction disks 34 (a circular limitation is not intended by the term “disk” but rather any desired perimetrical shape may be used) is positioned, in alternating manner, with a plurality of thrust washers 36.
- a plurality of thrust washers 36 there are shown two friction disks and three thrust washers. It will be understood however that the number of disks and thrust washers is not limited to that shown but that more or fewer could be utilized in particular applications, even including none. If none is desired, then in one embodiment the housing surface facing the armature and the armature surface opposing the identified housing surface will be hardened or otherwise treated to prolong wear resistance.
- the friction disks 34 are driven by (or drive through) shaft 16 in one embodiment through the use of a hexagonal opening 38 (see Figure 6) complimentary to a hexagonal drive profile 40 (see Figure 2) on shaft 16.
- a hexagonal drive shape has been employed in the embodiment illustrated, any geometric shape having sufficient drive capability for the application is substitutable for the hexagonal shape. This includes a splined connection, should one be desirable.
- Functionality is provided by the disks being driven at the axis thereof as will become more apparent hereinafter.
- the plurality of thrust washers 36 are configured to clear drive profile 40 with an opening 42 that is simply large enough to not engage whatever geometric profile is utilized relative to the washers.
- the thrust washers 36 include engagement tabs 44, which in one embodiment number four, evenly spaced around each thrust washer 36. Tabs 44 are intended to be engaged by at least one recess 46 in an armature 48 (see Figure 3, four shown). The tabs engaged with recesses 46 prevent relative rotational motion between the washers and the armature.
- Armature 48 includes a bearing opening 50 in which bearing 18 is received to support armature 48, although it is to be understood that the bearing depicted is optional and existing in the illustrated embodiment but could be eliminated in alternate embodiments without effect on operation of the device as herein disclosed. Armature 48 is axially displaceable along bearing 18 such that it may be actuated against the thrust washers and friction disks when it is desired to slow or stop relative rotation between shaft 16 and the housing and cover 12, 14. In one embodiment, it is necessary that the armature not have relative rotational motion capability with respect to the housing 12. Thus, as illustrated in figure 3, armature 48 is provided with engagement risers 52. Four risers 52 are illustrated although more or fewer could be used. In the illustrated embodiment, using four risers 52 and four recesses 46 maintains annular thickness of the armature 48.
- the disks 34 and washers 36 are illustrated apart from other structures.
- the washer tabs 44 as noted are intended to engage in recesses 46 for a non-rotational engagement with armature 48.
- the risers 52 engage grooves 54 (illustrated in figure 4). With this arrangement, the washers 36 are substantially rotationally immobile relative to the housing 12, which facilitates the purpose of the device. It will be understood that this is but one possibility of an arrangement for antirotation between the washers and armature, others functionally equivalent are substitutable as desired.
- the friction disks 34 must slide past the washers 36. Because of this arrangement, if a compressive load is applied to the washers/disks, the effective total friction rises and relative motion between the washers and clutching in various applications.
- the impetus for the compressive load in the depicted embodiment is an electromagnetic attractive force generated between the housing 12 and the armature 48.
- a coil 56 as illustrated in Figure 1, generates the electromagnetic force.
- the coil 56 is cradled in a bobbin 58 disposed within housing 12.
- One lead 60 (of two, the other not being visible in this view), electrically connected to the coil 56 is illustrated in Figure 1 for clarity.
- Coil 56 becomes magnetically active when a current is applied thereto.
- the magnetic properties of coil 56 are utilized to draw armature 48 towards the coil 56 thereby compressing thrust washers 36 and friction disks 34 between an inside surface 62 of armature 48 and a housing surface 64. Compression of washers 36 and disks 34 creates significant friction to be utilized in retarding relative rotation between shaft 16 and housing 12, as noted above.
- the device disclosed herein provides for a significantly longer life than prior art devices as it is capable of about forty-thousandths to about fifty- thousandths of an inch of wear in the friction generating members before losing selective braking or clutching power whereas the prior art is merely capable often thousandths of an inch of wear.
- the invention accomplishes this desirable result by causing the magnetic flux path of the device to flow from coil 56 to armature 48 and then to the housing in a direction substantially radial in orientation rather than axially (of the device) through the air gap between the housing and armature. This is contrary to what clutching and braking devices have done in the past.
- the creation of the radial flux path is occasioned by the addition to the armature 48 of a portion thereof radially concentrically positioned relative to a portion of the housing, such as a ring of material 66 positioned to extend from a planar portion 68 of armature 48 into an annular space 70 within which bobbin 58 and coil 56 are disposed.
- the ring 66 because it extends into the space 70 by a small amount, while providing a radial air gap 72 between the housing 12 and the armature 48, physically causes the flux path to flow substantially radially as consistent over a longer range. More specifically, the device exhibits a substantially uniform magnetic actuation force sustainable through a majority of an axial movement of the device irrespective of wear of the device.
- the prior art suffers a reduction in the magnetic actuation force as the discs and washers wear due to ordinary use of the device.
- the wear of these items does not affect the magnetic actuation force to any appreciable degree. This is what provides the benefit of the greater wear tolerance in the present arrangement.
- the air gap is not in a wear path of the device (the wear path being axial due to frictional wear of the disks and washers in an axial direction).
- the gap 72 therefore does not change in dimension but remains consistent regardless of the wear in the friction disks 34.
- the disks and washers in a clutching or braking system may be constructed at least partially of torque transfer materials having a kinetic coefficient of friction substantially the same as its static coefficient of friction or within about plus or minus 5 percent of 1 : 1. It is to be understood however that although benefit of the invention diminishes with increasing disparity between the kinetic coefficient of friction and the static coefficient of friction, benefits hereof are still largely exhibited up to about 20 percent difference.
- the material is a bearing material of nylon with a PTFE (Polytetrafluoroethylene) or other low friction additive and exhibits a ratio of static coefficient of friction to kinetic coefficient of friction of about 1.05.
- the device as detailed hereinabove provides not only for greater wear tolerance in use but also allows for selectivity in the amount of braking force or clutching engagement it will impart to a particular system. This benefit is occasioned by the fact that the device is ultimately controlled by the amount of current put to the coil 56.
- the greater the current applied to the coil the greater the magnetic field generated thereby.
- the greater the magnetic field the stronger the pull on the armature, and consequently the greater the compression of the friction disks.
- the amount of friction generated between the thrust washers and friction disks therefore can be varied as a function of the applied current.
- the above-described embodiment is one possible embodiment utilizing the radial air gap and flux path disclosed. It should also be appreciated however that the essential features of this concept, i.e. braking or clutching can also be carried out using the radial air gap and flux path but without utilizing friction disks or thrust washers.
- the armature would be rotatable relative to the housing when the coil was not energized and would be pulled into frictional contact with the housing when the coil is energized. This would promote wear of the housing and the armature but with suitable selection of materials, the device would work acceptably.
- the braking or clutching device as disclosed herein is not limited to industrial applications. Rather the device is useful for many different arrangements such as a human tactile interface arrangements, responsive to a control algorithm, employed in devices such as video games where tactile feedback is useful to enhance the gaming experience.
- the torque transfer devices disclosed herein are useful in steer by wire applications in order to provide tactile feedback to a pilot of a plane, boat or motor vehicle.
- the devices disclosed herein are useful for tensioning systems where a sensor system is configured to sense tension in, for example, a web and provide sensory information to a controller that then actuates a braking of clutching device provided in the system to modify the tension in the web.
- the devices disclosed herein are useful in variable torque proportioning devices, etc. In short, the devices as disclosed herein are applicable to any system wherein control over torque transfer is useful.
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Braking Arrangements (AREA)
- Mechanical Operated Clutches (AREA)
Abstract
An electric braking or clutching device includes a housing (12); an armature (48) having an axis and disposed at the housing, the armature and the housing defining a radial air gap therebetween; and a coil (56) configured to generate, when energized, a magnetic field at the housing (12) and armature, a flux path of the field extending from the coil (56) into the armature (48), from the armature (48) into the housing (12), and from the housing (12) back to the coil (56), with the direction of the flux path from the armature (48) into the housing (12) being substantially radial in orientation.
Description
A BRAKING OR CLUTCHING DEVICE
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. Application Serial No. 11/415,263, filed May 1, 2006, which is incorporated herein by reference in its entirety.
BACKGROUND
[0002] Devices used for braking or clutching are common in industry. It is often desirable to selectively control speed or torque of a rotatable component of a device or to selectively engage a rotatable component. Such devices are utilized in industry for many and varied applications including actuators in assembly lines, automated systems, etc.
[0003] Currently, braking and clutching duties are handled by devices including magnetorheological fluid based devices and spring-based devices. While commercially available devices generally operate as marketed and are effective for some applications, they are expensive, lack adjustability, or both.
[0004] Since greater economy and adjustability are always desirable, improvements are always well received.
SUMMARY OF THE INVENTION
[0004] An electric braking or clutching device includes a housing; an armature having an axis and disposed at the housing, the armature and the housing defining a radial air gap therebetween; and a coil configured to generate, when energized, a magnetic field at the housing and armature, a flux path of the field extending from the coil into the armature, from the armature into the housing, and from the housing back to the coil, with the direction of the flux path from the armature into the housing being substantially radial in orientation.
[0005] A braking or clutching device includes a first plurality of discs rotationally fixed to one of a housing or a shaft; and at least one second disc interengaged with the first plurality of discs and rotationally fixed to the other of the housing or the shaft, at least one of the first plurality of discs and the at least one second disc presenting a contact surface, for
contact with another of the first plurality of discs and at least one second disc, the surface comprising a low friction bearing material having a kinetic coefficient of friction substantially the same as its static coefficient of friction.
[0006] A magnetically actuable device includes a housing; and an armature disposed at the housing and axially movable relative to the housing, the device having a substantially uniform magnetic actuation force sustainable through a majority of an axial movement of the device irrespective of wear of the device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The above, as well as other advantages of the present invention, will become readily apparent to those skilled in the art from the following detailed description of a preferred embodiment when considered in the light of the accompanying drawings in which:
[0008] Figure 1 is a cross section view of a selective engagement device;
[0009] Figure Ia is a plan view of the device illustrating the section line for figure 1;
[0010] Figure 2 is a perspective view of a shaft of the device;
[0011] Figure 3 is a perspective view of an armature of the device;
[0012] Figure 4 is a perspective view of a housing of the device;
[0013] Figure 5 is a plan view of a thrust washer of the device;
[0014] Figure 6 is a plan view of a friction disk of the device; and
[0015] Figure 7 is an enlarged view of circumscribed area 7-7 in figure 1.
[0016] Figure 8 is the view of Figure 7 with the flux path illustrated by a heavy black line.
DETAILED DESCRIPTION OF THE DRAWINGS
[0017] Prior to discussing the figures, it is important to point out that although the drawings and description hereof are directed to a device where the housing is outwardly adjacent the armature, the concepts disclosed herein are applicable to the housing being inwardly adjacent the armature. The armature may also be adjacent the housing in a sideways manner. Referring to Figure 1 , a selective engagement device 10 is generally depicted in cross section. It is important to note that the section line as depicted is not a diametral line but rather is that illustrated in figure Ia. The device includes a coil housing 12 and cover 14. Supported within the coil housing 12 and cover 14 are a rotary shaft 16 supported by bearings 18, 20 and 22. A retention ring 24 is positionable in a groove 26 adjacent to bearing 22 while retention ring 28 is positioned in groove 30 adjacent bearing 18 to retain the shaft 16 in its desired position relative to the housing 12 and cover 14. Further provided is a seal 32 to maintain the environment internal to housing 12 and cover 14.
[0018] A plurality of friction disks 34 (a circular limitation is not intended by the term "disk" but rather any desired perimetrical shape may be used) is positioned, in alternating manner, with a plurality of thrust washers 36. In the illustrated embodiment, there are shown two friction disks and three thrust washers. It will be understood however that the number of disks and thrust washers is not limited to that shown but that more or fewer could be utilized in particular applications, even including none. If none is desired, then in one embodiment the housing surface facing the armature and the armature surface opposing the identified housing surface will be hardened or otherwise treated to prolong wear resistance. Returning to the illustrated embodiment, the friction disks 34 are driven by (or drive through) shaft 16 in one embodiment through the use of a hexagonal opening 38 (see Figure 6) complimentary to a hexagonal drive profile 40 (see Figure 2) on shaft 16. It is to be appreciated that while a hexagonal drive shape has been employed in the embodiment illustrated, any geometric shape having sufficient drive capability for the application is substitutable for the hexagonal shape. This includes a splined connection, should one be desirable. Functionality is provided by the disks being driven at the axis thereof as will become more apparent hereinafter. The plurality of thrust washers 36, on the other hand are configured to clear drive profile 40 with an opening 42 that is simply large enough to not engage whatever geometric profile is utilized
relative to the washers. The thrust washers 36 include engagement tabs 44, which in one embodiment number four, evenly spaced around each thrust washer 36. Tabs 44 are intended to be engaged by at least one recess 46 in an armature 48 (see Figure 3, four shown). The tabs engaged with recesses 46 prevent relative rotational motion between the washers and the armature.
[0019] Armature 48 includes a bearing opening 50 in which bearing 18 is received to support armature 48, although it is to be understood that the bearing depicted is optional and existing in the illustrated embodiment but could be eliminated in alternate embodiments without effect on operation of the device as herein disclosed. Armature 48 is axially displaceable along bearing 18 such that it may be actuated against the thrust washers and friction disks when it is desired to slow or stop relative rotation between shaft 16 and the housing and cover 12, 14. In one embodiment, it is necessary that the armature not have relative rotational motion capability with respect to the housing 12. Thus, as illustrated in figure 3, armature 48 is provided with engagement risers 52. Four risers 52 are illustrated although more or fewer could be used. In the illustrated embodiment, using four risers 52 and four recesses 46 maintains annular thickness of the armature 48.
[0020] Referring to figures 5 and 6, the disks 34 and washers 36 are illustrated apart from other structures. The washer tabs 44 as noted are intended to engage in recesses 46 for a non-rotational engagement with armature 48. To complete the nonrelational engagement from the washers 36 to housing 12, the risers 52 engage grooves 54 (illustrated in figure 4). With this arrangement, the washers 36 are substantially rotationally immobile relative to the housing 12, which facilitates the purpose of the device. It will be understood that this is but one possibility of an arrangement for antirotation between the washers and armature, others functionally equivalent are substitutable as desired.
[0021] With the washers 36 immobile and the friction disks 34 sandwiched between the washers 36 (and configured to rotate with the shaft 16) the friction disks must slide past the washers 36. Because of this arrangement, if a compressive load is applied to the washers/disks, the effective total friction rises and relative motion between the washers and
clutching in various applications. The impetus for the compressive load in the depicted embodiment is an electromagnetic attractive force generated between the housing 12 and the armature 48. It is noted here that a specific relationship for the armature and housing is disclosed herein that causes a flux path of the device to be unique and as a consequence causes the air gap between the housing and armature to remain constant throughout the service life of the device irrespective of wear of the device and without need for adjustment of any kind. This will be detailed hereunder.
[0022] A coil 56, as illustrated in Figure 1, generates the electromagnetic force. The coil 56 is cradled in a bobbin 58 disposed within housing 12. One lead 60 (of two, the other not being visible in this view), electrically connected to the coil 56 is illustrated in Figure 1 for clarity. Coil 56 becomes magnetically active when a current is applied thereto. The magnetic properties of coil 56 are utilized to draw armature 48 towards the coil 56 thereby compressing thrust washers 36 and friction disks 34 between an inside surface 62 of armature 48 and a housing surface 64. Compression of washers 36 and disks 34 creates significant friction to be utilized in retarding relative rotation between shaft 16 and housing 12, as noted above. The device disclosed herein provides for a significantly longer life than prior art devices as it is capable of about forty-thousandths to about fifty- thousandths of an inch of wear in the friction generating members before losing selective braking or clutching power whereas the prior art is merely capable often thousandths of an inch of wear. The invention accomplishes this desirable result by causing the magnetic flux path of the device to flow from coil 56 to armature 48 and then to the housing in a direction substantially radial in orientation rather than axially (of the device) through the air gap between the housing and armature. This is contrary to what clutching and braking devices have done in the past. The creation of the radial flux path is occasioned by the addition to the armature 48 of a portion thereof radially concentrically positioned relative to a portion of the housing, such as a ring of material 66 positioned to extend from a planar portion 68 of armature 48 into an annular space 70 within which bobbin 58 and coil 56 are disposed. The ring 66, because it extends into the space 70 by a small amount, while providing a radial air gap 72 between the housing 12 and the armature 48, physically causes the flux path to flow substantially radially as
consistent over a longer range. More specifically, the device exhibits a substantially uniform magnetic actuation force sustainable through a majority of an axial movement of the device irrespective of wear of the device. Stated alternately, the prior art suffers a reduction in the magnetic actuation force as the discs and washers wear due to ordinary use of the device. In the present invention, the wear of these items does not affect the magnetic actuation force to any appreciable degree. This is what provides the benefit of the greater wear tolerance in the present arrangement. It is the air gap 72 between the housing 12 and the armature 48, because it is radially oriented that is responsible for the benefit. The air gap is not in a wear path of the device (the wear path being axial due to frictional wear of the disks and washers in an axial direction). The gap 72 therefore does not change in dimension but remains consistent regardless of the wear in the friction disks 34. Prevention of change in the dimension of the air gap 72 through which the flux passes contributes to the steady force generated over the life of the device (e.g. between about .020 inch and .070 inch of axial wear in the device. Referring to figure 7, an enlarged view of a portion of figure 1 allows for illustration of the air gap 72. The flux path through the air gap is illustrated in figure 8 by a heavy black line 74.
[0023] Providing further benefit to the devices disclosed herein is the additional teaching hereof that the disks and washers in a clutching or braking system may be constructed at least partially of torque transfer materials having a kinetic coefficient of friction substantially the same as its static coefficient of friction or within about plus or minus 5 percent of 1 : 1. It is to be understood however that although benefit of the invention diminishes with increasing disparity between the kinetic coefficient of friction and the static coefficient of friction, benefits hereof are still largely exhibited up to about 20 percent difference. In one embodiment, the material is a bearing material of nylon with a PTFE (Polytetrafluoroethylene) or other low friction additive and exhibits a ratio of static coefficient of friction to kinetic coefficient of friction of about 1.05. It is further to be noted that while the foregoing disclosure relates in large part to an electromagnetic device, the utilization of a torque transfer material having the stated range of ratio of static to kinetic coefficient of friction is not restricted to electrically or magnetically actuable devices but may
actuable devices, etc. The property as stated, and as is implied by the statement itself, means that there is very little "stick-slip" action in the system of the invention. As an astute reader might posit, such properties also indicate a relatively low production of usable friction. While this condition might be considered questionable for a clutching/braking device, the benefits of avoidance of "stick-slip" are more important. This is especially the case in view of the fact that the loss in overall friction in the system can be easily compensated for by increasing the radial distance from the axis of the device to the friction surface, increasing the frictional area, or increasing the number of frictional interfaces (disks and washers) in the system. It is also contemplated to use more than one of these compensating arrangements together in some applications.
[0024] The device as detailed hereinabove provides not only for greater wear tolerance in use but also allows for selectivity in the amount of braking force or clutching engagement it will impart to a particular system. This benefit is occasioned by the fact that the device is ultimately controlled by the amount of current put to the coil 56. The greater the current applied to the coil, the greater the magnetic field generated thereby. The greater the magnetic field the stronger the pull on the armature, and consequently the greater the compression of the friction disks. The amount of friction generated between the thrust washers and friction disks therefore can be varied as a function of the applied current.
[0025] It is noted that the above-described embodiment is one possible embodiment utilizing the radial air gap and flux path disclosed. It should also be appreciated however that the essential features of this concept, i.e. braking or clutching can also be carried out using the radial air gap and flux path but without utilizing friction disks or thrust washers. In such embodiment, the armature would be rotatable relative to the housing when the coil was not energized and would be pulled into frictional contact with the housing when the coil is energized. This would promote wear of the housing and the armature but with suitable selection of materials, the device would work acceptably.
[0026] It is to be understood that the braking or clutching device as disclosed herein is not limited to industrial applications. Rather the device is useful for many different
arrangements such as a human tactile interface arrangements, responsive to a control algorithm, employed in devices such as video games where tactile feedback is useful to enhance the gaming experience. Moreover, the torque transfer devices disclosed herein are useful in steer by wire applications in order to provide tactile feedback to a pilot of a plane, boat or motor vehicle. Further the devices disclosed herein are useful for tensioning systems where a sensor system is configured to sense tension in, for example, a web and provide sensory information to a controller that then actuates a braking of clutching device provided in the system to modify the tension in the web. Yet still the devices disclosed herein are useful in variable torque proportioning devices, etc. In short, the devices as disclosed herein are applicable to any system wherein control over torque transfer is useful.
[0027] While preferred embodiments have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustration and not limitation. '
Claims
Claim 1. An electric braking or clutching device comprising:
a housing;
an armature having an axis and disposed at the housing, the armature and the housing defining a radial air gap therebetween; and
a coil configured to generate, when energized, a magnetic field at the housing and armature, a flux path of the field extending from the coil into the armature, from the armature into the housing, and from the housing back to the coil, with the direction of the flux path from the armature into the housing being substantially radial in orientation.
Claim 2. An electric braking or clutching device as claimed in claim 1 wherein the armature includes a portion thereof radially concentrically positioned relative to the housing.
Claim 3. An electric braking or clutching device as claimed in claim 1 wherein includes a thereof radially concentrically positioned portion of the armature is radially inwardly positioned of the housing.
Claim 4. An electric braking or clutching device as claimed in claim 1 wherein the armature includes a planar portion and the radially concentrically positioned portion is a ring extending axially therefrom.
Claim 5. An electric braking or clutching device as claimed in claim 1 wherein the air gap is of a substantially fixed, radial dimension irrespective of wear of the device.
Claim 6. An electric braking or clutching device as claimed in claim 1 wherein the device includes at least one friction disk disposed between the housing and the armature.
Claim 7. An electric braking or clutching device as claimed in claim 6 wherein the friction disk is subjectable to an axial compressive load.
Claim 8. An electric braking or clutching device as claimed in claim 6 wherein the friction disk is rotationally fixed to a shaft supported at the housing.
Claim 9. An electric braking or clutching device as claimed in claim 8 wherein the disk is rotationally fixed to the shaft by a geometrically shaped opening therein complementary to a geometrically shaped portion of the shaft.
Claim 10. An electric braking or clutching device as claimed in claim 6 wherein the device further includes a plurality of thrust washers alternately positioned relative to the friction disk.
Claim 11. An electric braking or clutching device as claimed in claim 10 wherein the plurality of thrust washers include at least one antirotation configuration to inhibit rotation between the washer and armature.
Claim 12. An electric braking or clutching device as claimed in claim 1 wherein the direction of the flux path from the housing into the armature is substantially radial.
Claim 13. An electric braking or clutching device comprising:
a housing;
an armature in axially displaceable operable communication with the housing and defining between the housing and the armature a fixed radial dimension radial air gap; and
a source for a magnetic field disposed at the device, a magnetic flux of the field extending across the radial air gap more radially than axially, when energized.
Claim 14. An electric braking or clutching device comprising:
a housing;
a coil disposed at the housing, the coil being capable of generating a magnetic field when energized; and
an armature disposed at the housing and defining a radial air gap between the housing and the armature, the air gap being a part of a flux path when the device is energized, the radial air gap being maintained at a consistent radial dimension, with movement of the armature relative to the housing in an axial direction thereof.
Claim 15. An electric braking or clutching device as claimed in claim 14 wherein the air gap is radially outwardly positioned of the housing.
Claim 16. An electric braking or clutching device as claimed in claim 14 wherein the air gap is radially inwardly positioned of the housing.
Claim 17. A braking or clutching device comprising:
a first plurality of discs rotationally fixed to one of a housing or a shaft; and
at least one second disc interengaged with the first plurality of discs and rotationally fixed to the other of the housing or the shaft, at least one of the first plurality of discs and the at least one second disc presenting a contact surface, for contact with another of the first plurality of discs and at least one second disc, the surface comprising a low friction bearing material having a kinetic coefficient of friction substantially the same as its static coefficient of friction.
Claim 18. A braking or clutching device as claimed in claim 17 wherein the kinetic coefficient of friction is within about five percent of the static coefficient of friction.
Claim 19. A braking or clutching device as claimed in claim 17 wherein the kinetic coefficient of friction of the material is within about twenty percent of the static coefficient of
Claim 20. A magnetically actuable device comprising:
a housing; and
an armature disposed at the housing and axially movable relative to the housing, the device having a substantially uniform magnetic actuation force sustainable through a majority of an axial movement of the device irrespective of wear of the device.
Claim 21. A magnetically actuable device as claimed in claim 20 wherein the device further comprises a coil that upon application of an electric current thereto generates a magnetic field having a flux path, the armature and the housing being configured to facilitate passing of the flux between the housing and armature in a substantially radial orientation.
Claim 22. A magnetically actuable device as claimed in claim 20 wherein the device includes an air gap through which a flux from an electrically actuable magnetic field passes, the air gap being located out of a wear path of the device.
Claim 23. A tactile feedback interface arrangement comprising:
an electric braking and clutching device responsive to a control algorithm to impart tactile feedback to a human the arrangement including:
a housing;
an armature having an axis and disposed at the housing, the armature and the housing defining a radial air gap therebetween; and
a coil configured to generate, when energized, a magnetic field at the housing and armature, a flux path of the field extending from the coil into the armature, from the armature into the housing, and from the housing back to the coil, with the direction of the flux path from the armature into the housing being substantially radial in orientation.
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AT07776580T ATE496232T1 (en) | 2006-05-01 | 2007-04-30 | BRAKE OR CLUTCH DEVICE |
JP2009509671A JP5379679B2 (en) | 2006-05-01 | 2007-04-30 | Braking or clutch device |
EP07776580A EP2024657B1 (en) | 2006-05-01 | 2007-04-30 | A braking or clutching device |
DE602007012088T DE602007012088D1 (en) | 2006-05-01 | 2007-04-30 | BRAKE OR CLUTCH DEVICE |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/415,263 | 2006-05-01 | ||
US11/415,263 US20070251775A1 (en) | 2006-05-01 | 2006-05-01 | Selective engagement apparatus and method |
US11/742,185 | 2007-04-30 | ||
US11/742,185 US7717241B2 (en) | 2006-05-01 | 2007-04-30 | Braking or clutching device |
Publications (4)
Publication Number | Publication Date |
---|---|
WO2007130421A2 true WO2007130421A2 (en) | 2007-11-15 |
WO2007130421A3 WO2007130421A3 (en) | 2008-04-10 |
WO2007130421A8 WO2007130421A8 (en) | 2008-12-24 |
WO2007130421A9 WO2007130421A9 (en) | 2011-02-03 |
Family
ID=38668262
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US2007/010565 WO2007130421A2 (en) | 2006-05-01 | 2007-04-30 | A braking or clutching device |
Country Status (6)
Country | Link |
---|---|
US (2) | US7717241B2 (en) |
EP (2) | EP2302250B1 (en) |
JP (2) | JP5379679B2 (en) |
CN (1) | CN102278399B (en) |
AT (1) | ATE496232T1 (en) |
WO (1) | WO2007130421A2 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2010109319A1 (en) * | 2009-03-27 | 2010-09-30 | Eaton Corporation | Electromagnetic inertia brake for a multiple-ratio power transmission |
Families Citing this family (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
MX2008014783A (en) | 2008-02-05 | 2009-08-27 | Krueger Int Inc | Chair shell with integral hollow contoured support. |
US9422990B2 (en) * | 2012-04-21 | 2016-08-23 | Dayco Ip Holdings, Llc | Clutch for linking an input shaft with a drive mechanism and methods of coupling control using the same |
JP6202964B2 (en) * | 2013-09-27 | 2017-09-27 | 住友重機械工業株式会社 | forklift |
US9656746B2 (en) * | 2014-01-31 | 2017-05-23 | Bell Helicopter Textron Inc. | Magnetorheological haptic trim actuator |
US9308990B2 (en) * | 2014-05-30 | 2016-04-12 | Goodrich Corporation | Voice coil linear activated park brake |
US9656745B2 (en) * | 2015-01-30 | 2017-05-23 | Bell Helicopter Textron Inc. | Magnetorheological actuator with torsional spring |
RU169054U1 (en) * | 2016-08-19 | 2017-03-02 | Акционерное общество "Электропривод" | Electromagnetic clutch-brake for atomic reactor rod drive motor |
RU2662270C2 (en) * | 2016-08-19 | 2018-07-25 | Акционерное общество "Электропривод" | Electromagnetic clutch-brake for the electric motor of the rod actuator of the nuclear reactor |
CN109595278A (en) * | 2018-11-28 | 2019-04-09 | 西安航天动力测控技术研究所 | A kind of high speed sheet electromagnetic brake |
CN111318011B (en) * | 2020-02-28 | 2023-03-21 | 歌尔科技有限公司 | Game paddle and rocker feedback force device thereof |
FR3113709A1 (en) * | 2020-08-31 | 2022-03-04 | Christian Menard | electromagnetic device associated mechanical amplifier DEAMEA |
CN116997365A (en) * | 2020-11-06 | 2023-11-03 | 加利福尼亚大学董事会 | SIRNA nanobowl-mediated COVID-19 intervention |
Family Cites Families (53)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2378108A (en) * | 1937-07-29 | 1945-06-12 | Ryba Anton | Electromagnetic multiple-disk clutch |
US2597388A (en) * | 1946-09-14 | 1952-05-20 | Lavaud Robert Sensaud De | Electromagnetic clutch |
US3268044A (en) * | 1964-04-13 | 1966-08-23 | Gen Scientific Corp | Coupling device |
US3422942A (en) * | 1966-11-17 | 1969-01-21 | Bendix Corp | Stationary coil electromagnetic clutch |
JPS4634900Y1 (en) * | 1966-12-01 | 1971-12-02 | ||
US3446322A (en) * | 1967-09-12 | 1969-05-27 | Stearns Electric Corp | Electromagnetic clutch with auxiliary clutch or brake independently energized |
US3789966A (en) * | 1971-03-31 | 1974-02-05 | Bendix Corp | Self-adjusting electromagnetic disc clutch |
US3734245A (en) * | 1971-10-01 | 1973-05-22 | Motor Wheel Corp | Electric brake |
US3899061A (en) * | 1974-04-29 | 1975-08-12 | Warner Electric Brake & Clutch | Excitation control for normally engaged, electrically released magnetic coupling |
DE2601121A1 (en) | 1975-01-15 | 1976-07-22 | Matrix Eng Ltd | Electromagnetic brake or clutch - reduces stray magnetic flux with concentric coils with adjacent like poles |
DE2616393A1 (en) | 1976-04-14 | 1977-11-03 | Deutsche Bundesbahn | Dampened railway wheels and axles - has resonant frequencies set to eliminate vibration and reduce rail wear |
DE2638944A1 (en) | 1976-08-28 | 1978-03-02 | Zahnradfabrik Friedrichshafen | MAGNETIC ACTUATED FRICTION CLUTCH OR BRAKE |
GB1599434A (en) * | 1977-05-06 | 1981-10-07 | Krupp Ag Huettenwerke | Vibration absorbing track wheel |
DE2816561C3 (en) | 1978-04-17 | 1981-10-15 | Krupp Stahl Ag, 4630 Bochum | System of rail wheel and track for rail vehicles |
US4201281A (en) * | 1978-05-22 | 1980-05-06 | Warner Electric Brake & Clutch Company | Electromagnetic clutch having a contractible friction shoe |
DE2835020C2 (en) | 1978-08-10 | 1983-10-20 | Krupp Stahl Ag, 4630 Bochum | Vibration damper |
DE2903362A1 (en) * | 1979-01-29 | 1980-07-31 | Demag Ag Mannesmann | Electromagnetic air brake for rotary machine - combines flat and plunger armature attraction effects with electromagnet excitation to brake shaft |
DE2922585B1 (en) * | 1979-06-02 | 1980-12-11 | Krupp Ag Huettenwerke | Vibration absorber for resonance vibrations of rotating bodies |
US4567975A (en) * | 1984-02-17 | 1986-02-04 | Warner Electric Brake & Clutch Co. | Apparatus and method for controlling the engagement of a gap-type electromagnetic coupling and for alleviating engagement noise |
DE3434116C2 (en) | 1984-09-17 | 1986-11-20 | Fa. Carl Zeiss, 7920 Heidenheim | Electromagnetic brake |
JPH0517454Y2 (en) * | 1986-12-26 | 1993-05-11 | ||
US4717865A (en) * | 1987-05-29 | 1988-01-05 | Westinghouse Electric Corp. | Transportation apparatus |
US4951797A (en) * | 1988-10-25 | 1990-08-28 | Dana Corporation | Electromagnetic coupling disc |
US4982825A (en) * | 1989-05-11 | 1991-01-08 | Sepal | Torque and air gap adjustment mechanism for spring engaged brake or clutch |
US4997067A (en) * | 1989-06-26 | 1991-03-05 | Fenner America, Inc. | Friction apparatus |
US4938321A (en) * | 1989-07-21 | 1990-07-03 | Force Control Industries, Inc. | Liquid cooled brake apparatus |
JP2762616B2 (en) * | 1989-10-09 | 1998-06-04 | トヨタ自動車株式会社 | Friction multi-plate differential limiter |
US5121018A (en) * | 1991-03-04 | 1992-06-09 | Lucas Aerospace Power Equipment Corporation | Latching brake using permanent magnet |
US5185542A (en) * | 1991-08-28 | 1993-02-09 | Electroid Company | Electromagnetic pulse operated bi-stable brake |
CN2113377U (en) * | 1992-01-18 | 1992-08-19 | 天津市机床电器总厂 | Bidirectional electromagnet clutch with brake and clutch function |
JPH05194936A (en) * | 1992-01-23 | 1993-08-03 | Jidosha Denki Kogyo Co Ltd | Friction material composition |
JP2585437Y2 (en) * | 1992-02-18 | 1998-11-18 | 栃木富士産業株式会社 | Electromagnetic multi-plate clutch |
US5603395A (en) * | 1992-03-05 | 1997-02-18 | Easom Engineering & Mfg. Corp. | Electrically actuated disc stack having low response time due to reduced residual magnetism for use in drives, brakes and combinations thereof |
GB9302623D0 (en) * | 1993-02-10 | 1993-03-24 | Ti Matrix Eng Ltd | Brake device |
FR2718130B1 (en) * | 1994-04-05 | 1996-06-21 | Europ Propulsion | Method for applying anti-oxidation protection to brake discs made of carbon-containing composite material. |
JPH09229105A (en) | 1996-02-27 | 1997-09-02 | Teijin Seiki Co Ltd | Self-holding type coupling device |
FR2750650B1 (en) | 1996-07-03 | 1998-11-06 | Valdunes | METHOD FOR SOUNDPROOFING A RAILWAY WHEEL AND SOUNDPROOFED RAILWAY WHEEL |
JP2001050305A (en) * | 1999-08-06 | 2001-02-23 | Denso Corp | Clutch device for vehicle |
JP2001050307A (en) * | 1999-08-11 | 2001-02-23 | Tochigi Fuji Ind Co Ltd | Coupling and differential device |
US6405837B1 (en) * | 2000-02-10 | 2002-06-18 | Mico Incorporated | Combined parking and service brake |
FR2810088B1 (en) * | 2000-06-07 | 2004-06-04 | Skf France | BRAKE BEARING |
JP3523607B2 (en) * | 2001-04-03 | 2004-04-26 | 本田技研工業株式会社 | Magnetic flux detector |
US6789456B2 (en) * | 2001-08-29 | 2004-09-14 | Battelle Memorial Institute | Braking system |
JP2003074599A (en) * | 2001-09-03 | 2003-03-12 | Honda Motor Co Ltd | Magnetic flux density detector for electromagnetic clutch |
US6854573B2 (en) * | 2001-10-25 | 2005-02-15 | Lord Corporation | Brake with field responsive material |
GB2390885A (en) * | 2002-07-17 | 2004-01-21 | Bombardier Transp Gmbh | Rail vehicle wheel set with torsional vibration damping |
JP2004217790A (en) * | 2003-01-15 | 2004-08-05 | Dainatsukusu:Kk | Wet friction material |
JP2004308903A (en) * | 2003-04-07 | 2004-11-04 | Luk Lamellen & Kupplungsbau Beteiligungs Kg | Electromagnetic friction clutch |
JP2005029653A (en) * | 2003-07-10 | 2005-02-03 | Hitachi Ltd | Dry friction material |
US7140475B1 (en) * | 2004-05-19 | 2006-11-28 | Bruno Independent Living Aids, Inc. | Brake |
DE102005042593A1 (en) * | 2004-09-08 | 2006-03-30 | Continental Teves Ag & Co. Ohg | Combined hydraulic operating and hand brake operating method for motor vehicle, involves activating interlocking device by movement of transmission unit whose position is determined by electrical resistance test |
CN2766442Y (en) * | 2005-01-26 | 2006-03-22 | 连云港市雄鹰电工电子研究所有限公司 | Electromagnetic brake motor |
DE202006000469U1 (en) * | 2006-01-13 | 2006-03-09 | Intorq Gmbh & Co. Kg | Brake for an automobile trunk lid mechanism, operated by an electromotor, has an electromagnet assembly and a third switching mode with a limited braking action when the coils are not energized |
-
2007
- 2007-04-30 WO PCT/US2007/010565 patent/WO2007130421A2/en active Search and Examination
- 2007-04-30 CN CN201110198061.XA patent/CN102278399B/en not_active Expired - Fee Related
- 2007-04-30 AT AT07776580T patent/ATE496232T1/en not_active IP Right Cessation
- 2007-04-30 US US11/742,185 patent/US7717241B2/en not_active Expired - Fee Related
- 2007-04-30 JP JP2009509671A patent/JP5379679B2/en not_active Expired - Fee Related
- 2007-04-30 EP EP10191195A patent/EP2302250B1/en not_active Not-in-force
- 2007-04-30 EP EP07776580A patent/EP2024657B1/en not_active Not-in-force
-
2010
- 2010-03-04 US US12/717,619 patent/US8371423B2/en not_active Expired - Fee Related
-
2013
- 2013-02-21 JP JP2013031852A patent/JP2013152024A/en active Pending
Non-Patent Citations (1)
Title |
---|
None |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2010109319A1 (en) * | 2009-03-27 | 2010-09-30 | Eaton Corporation | Electromagnetic inertia brake for a multiple-ratio power transmission |
CN102369369A (en) * | 2009-03-27 | 2012-03-07 | 伊顿公司 | Electromagnetic inertia brake for a multiple-ratio power transmission |
US8397893B2 (en) | 2009-03-27 | 2013-03-19 | Eaton Corporation | Electromagnetic inertia brake for a multiple-ratio power transmission |
CN102369369B (en) * | 2009-03-27 | 2014-02-19 | 伊顿公司 | Electromagnetic inertia brake for a multiple-ratio power transmission |
CN103711818A (en) * | 2009-03-27 | 2014-04-09 | 伊顿公司 | Electromagnetic inertia brake for a multiple-ratio power transmission |
Also Published As
Publication number | Publication date |
---|---|
CN102278399A (en) | 2011-12-14 |
EP2302250B1 (en) | 2012-07-04 |
CN102278399B (en) | 2014-01-29 |
ATE496232T1 (en) | 2011-02-15 |
EP2024657B1 (en) | 2011-01-19 |
JP2009536308A (en) | 2009-10-08 |
WO2007130421A9 (en) | 2011-02-03 |
WO2007130421A8 (en) | 2008-12-24 |
US20100155189A1 (en) | 2010-06-24 |
US8371423B2 (en) | 2013-02-12 |
US20070257552A1 (en) | 2007-11-08 |
EP2302250A1 (en) | 2011-03-30 |
EP2024657A2 (en) | 2009-02-18 |
WO2007130421A3 (en) | 2008-04-10 |
JP5379679B2 (en) | 2013-12-25 |
US7717241B2 (en) | 2010-05-18 |
JP2013152024A (en) | 2013-08-08 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP2024657B1 (en) | A braking or clutching device | |
US8490769B2 (en) | Lever applied solenoid clutch actuator | |
CA2766108C (en) | Ball-ramp clutch | |
JP2009536308A5 (en) | ||
US5406180A (en) | Electric motor brake | |
JPH04228934A (en) | Brake mechanism | |
WO2014133990A2 (en) | Dynamic brake | |
JP5878755B2 (en) | Brake device | |
US20070251775A1 (en) | Selective engagement apparatus and method | |
US6637569B1 (en) | Ball ramp actuator with indexing plates | |
US3391768A (en) | Wear adjustor for friction devices | |
US10883554B2 (en) | Braking or clutch assembly for rotating shafts | |
JP7108506B2 (en) | Rotation transmission device | |
US11401988B2 (en) | Dual action magnetic brakes and related methods | |
US10830293B2 (en) | Torque limiter assembly | |
WO2019188576A1 (en) | Rotation braking apparatus | |
JP5027057B2 (en) | Rotation transmission device | |
JPS6028747A (en) | Motor with brake | |
JP4298742B2 (en) | Linear actuator | |
GB2588786A (en) | Static brake assembly |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 2007776580 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2009509671 Country of ref document: JP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 200780015644.6 Country of ref document: CN |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
DPE1 | Request for preliminary examination filed after expiration of 19th month from priority date (pct application filed from 20040101) |